Interface student (n:int) : real where n>=1. Returns a drawing from a Student distribution (also called t distribution) with n degrees of freedom. Note that as n increases, the Student density approaches the normal density. Indeed, even for n=8, the Student density is almost the same as the normal density. Raises Student exception, if n<1. Characteristics Mean: 0 Variance: 1/n-2 Density functions for student distributions: […]

Interface poisson(m:real) : int where m>0.0. Returns a drawing from a Poisson distribution with intensity m. Raises Poisson exception, if m<=0.0. Characteristics Mean: m Variance: m Probability mass functions for Poisson distributions: Example poisson(100.0) A company has a network with a certain load. Each second an average of 100 packets is sent to the network. The number of packets arriving to the network per second […]

Function for generating values from exponential distributions Interface exponential(r:real) : real where r>0.0. Gives a drawing from a exponential distribution with intensity r. Raises Exponential exception, if r<=0.0. Characteristics Mean: 1/r Variance: 1/r^2 Density functions for exponential distributions: Example exponential(1.0/4.0) Customers arrive at a post office for service. The time between two arrivals has a mean of 4 minutes. The inter-arrival time has an exponential […]

Interface erlang(n:int, r:real) : real where n>=1 and r>0.0. Returns a drawing from an n-Erlang distribution with intensity r. A drawing from an n-Erlang distribution can be derived by addition of n drawings from a exponential distribution. Raises Erlang exception, if n<1 or r<=0.0. Characteristics Mean: n/r Variance: n/r^2 Density functions for n-Erlang distributions: Example erlang(100,50.0) A shop gives each 100th customer a present. The […]